A desirable feature of mobile devices, such as mobile phones, laptops, PDAs, tablets, watches, music players, satellite navigation devices, cameras, is awareness of the device regarding the environment in which it is located, the current activity of the user and/or the circumstances in which the user finds himself, which together are called the “context” in the reminder of this description. Awareness of the context can help to improve the usability of the device, as well as the comfort and safety of its use.
Today's mobile devices are equipped with a large number of different types of sensors, which allow, inter alia, automatic activation and deactivation of individual functions or to change configuration of mobile devices, depending on the context. In most cases, the sensors indicate the context only indirectly. Therefore, there are carried out in the industry intense developments of effective and efficient methods for determining the context based on signals from various types of sensors.
A special case of context is a situation when a user of a mobile device drives a vehicle, such as a car. It is inadvisable in such circumstances, and in many countries prohibited by law to use such devices' functions so as make and receive voice calls and send and receive text messages. On the other hand, in those circumstances, it might be advantageous to activate other functions, such as navigation or download from an external database of information on known hazards on the roads and to inform the user of approaching them, with a message of a tone, voice, visual, or any combination thereof.
One of the known ways of detecting that the mobile device is located in a moving vehicle is to determine its approximate position on the basis of signals of base stations of cellular telephony and calculating average speed of the device based on the change of thus determined position in time. Position the device specified according to the aforementioned method is typically uncertainty in the order of few hundred meters to several kilometers. The greater the movement of the device in time, the greater the certainty of the weighted average speed. In a practical use this means a compromise between a delay in detection of movement in a vehicle of up to several minutes in the teens, and acceptance of frequent false classifications indicating the movement of the device in a vehicle at times when this is not actually happening.
Another well-known and used method of detecting that a mobile device is in a moving vehicle is to analyze the movement speed of the device using a global satellite positioning system, which provides much more accurate positioning than the signals of mobile communications base stations. Receivers of this type, however, consume significant amounts of energy, which significantly reduces the operating time of the mobile device using battery, often to such levels that are unacceptable to the user. Power consumption is reduced in many cases by less frequent switching the receiver on and less frequent positioning. However, this leads to a delay in detection of the identified context. Given the relatively small capacity of the batteries used in mobile devices, a compromise that can be achieved in this method between the movement detection delay and energy consumption can be unsatisfactory for many applications.
The patent application U.S. 2002/0128000 A1 discloses a system for use in a mobile communication device. The system includes a subsystem used for detection of movement of a device in a vehicle. Detection is performed by measuring the average speed of movement of the device, determined on the basis of signals from mobile telephony base stations or with a use of global satellite positioning system receiver.
An alternative and used on a industrial scale method for detecting use of a mobile device in a vehicle is to use vehicle-mounted short-range radio transmitter. The transmitter can be optionally activated only during operation of the vehicle, such as when the vehicle engine is running. The mobile device is equipped with a receiver compatible with the transmitter. It is assumed that the mobile device is used in a vehicle, when it is in range of the vehicle mounted transmitter. The disadvantage of this method is the necessity of an additional transmitter in the vehicle, while in the case of universal transceiver module, which is an equipment of the most modern mobile phones and some modern cars—at least a mindful configuration by a user. The configuration in this case is based on searching for a signal of the built-in transmitter of the vehicle, and storing a network address in the mobile device for future, unambiguous identification.
Patent application U.S. 2005/0255874 A1 discloses a system and method for detecting movement in a vehicle, which consists of a vehicle-mounted radio transmitter having low range, activated at a time when the vehicle is in use, and a mobile device equipped with a radio receiver. The mobile device detects that it is in the vehicle being used based on proximity of the signal of the transmitter mounted in the vehicle.
There are also ways of specifying a device context based one analysis of signals from different sensors, such as microphones, accelerometers, light sensors, magnetic field sensors, compasses, cameras and other. The information contained in the signals from the individual sensors are usually insufficient in order to determine, with a satisfactorily high degree of certainty, the device's context. Therefore, most of the known methods consist of parallel analysis of signals from multiple sensors. This leads to a substantial increase in the effectiveness of the classification, which, however, is achieved at the expense of increased power consumption, and thus a shorter time of operation of a battery-powered mobile device. The problem of reducing the energy consumption, if at all addressed in descriptions of individual methods, is typically solved by less frequent switching the sensors on and less frequent sampling. This leads, however, to extension of time after which a change of device context is detected.
The effectiveness of the classification of the signals from the individual sensors or groups of sensors, is also increased by the mechanisms of adaptive customization of classifiers' configuration based on feedback provided by users. They require the user to go through a conscious device learning process. There are also known methods for adaptation of classifiers determining the context based on the analysis of natural user interaction with the device, from which a real context at the time is determined. In the case of detecting movement in a vehicle, it may be a connection of the mobile phone to a speakerphone or executing applications for navigation. In this case, the adaptation of the classifiers' configuration, however, is much slower than in the case of intentional learning by the user. In the meantime, before the classifier's configuration adapts to the specific features indicating the contexts in which the user uses the device, the classification results can be far from satisfactory.
Patent application WO 2010/133770 A1 discloses a method of detecting a mobile device context. The method is based on retrieval of data from sensors, the data indicating a context in which the device and its user are found in, determining from the data their features, subjecting these features to a classification using an adaptive linear classifier and an adaptation of the classifier's configuration based on the designated features and feedback provided by the user of the device. Low complexity of the proposed classifier affects the low energy consumption compared to more complex methods of classification. Adaptation of configuration of the classifier based on information derived from user feedback, in turn increases the efficiency of classification. Feedback used to amend classifier's settings is provided directly by the user, indicating the correct classification result or voting positively or negatively on the result returned by the classifier, or indirectly inferred from actions taken by the user or the absence thereof.
Patent application publication US2009128286 discloses a system for controlling the use of electronic devices within an automobile includes a control module integrated into the operation of the automobile, wherein the control module is linked to the electrical system of the automobile and is controlled, monitored and updated via a graphical user interface of the automobile. The control module includes a mechanism for identifying use of electronic devices within the automobile, determining whether the usage is permitted and preventing usage of the electronic device if it is determined the usage is not permitted.
Patent application publication US2002128000 discloses a system for use with a mobile communication unit includes a service device configured to determine at least one service to be applied to affect at least one of incoming and outgoing communications to and from, respectively, the mobile communication unit, the service device being configured to determine the at least one service to be applied dependent upon a location of the mobile communication unit.
It would be desirable to define a method of detecting context of a mobile device and a mobile device having a module that enables detection of its context, which will reduce at least some of the disadvantages present in the prior art solution, and which will provide for a use of an alternative mechanism for the detection of context.